Demo: What S the Recipe for a Cloud

Demo: What’s the Recipe for a Cloud?

Pre-demo Questions:

1. Which will probably have more humidity (water vapor) in the air above it? ______

A) A part of the ocean having colder surface waters

B) A part of the ocean having warmer surface waters

2. In order for a cloud to form, the humid air must be cooled below its _____ point. ______

thermal ...... condensation ...... dew

3. As air is compressed (squeezed), will it become warmer, or will it become cooler?

4. As air is allowed to expand, what happens to its temperature? ______

5. What are condensation nuclei? Give two examples.

DEMO Procedures/Observations:

1. Part #1: Cold water in the bottle with squeezing.

Observations:

2. Part #2: Cold Water, match (smoke), and squeezing.

Observations:

3. Part #3: Hot Water and squeezing.

Observations:

4. Part #4: Hot Water, match (smoke), and squeezing.

Observations:

Questions:

1. Which of the four trials resulted in the best cloud formation? ______

2. Was cloud formation more impressive when smoke particles were present in the bottle? ______

3. Did the cloud appear when I caused high pressure on the air in the bottle (by squeezing), or when I caused low pressure (by releasing)?

4. Which provided more vapor in the bottle, hot or cold water? ______

5. Based on your findings, write out a recipe for cloud formation? (3 ingredients or conditions)

6. In your experiment, what served as the condensation nuclei? ______

7. Why did the cloud disappear when you squeezed the bottle? You must use the term “dew point” in your answer.

8. You can see clouds because they are made up of ______or ______ (Circle two answers.)

water vapor ...... water droplets ...... ice crystals

9. As air rises in the atmosphere, is it compressed, or does it expand? ______

10. What effect does this have on the air’s temperature?

11. Circle the letters of the situations that will contribute to cloud formation.

A. Moist air is forced upward as it encounters the Cascade Mountain Range.

B. Tomorrow’s forecast calls for an area of high pressure to be centered over your region.

C. During the afternoon, air over a large air force base begins to rise because it is so much hotter than air over the surrounding forest.

D. In autumn, the Santa Ana winds blow down from the mountain slopes of interior California out to the sea.

E. As part of the global circulation pattern, air 30 degrees north of the equator is sinking in an area called the horse latitudes.

F. An intense low pressure system moves across the Midwest.

G. A cold air mass from Canada pushes into a mass of warm humid air over Nebraska.